> There's a ton of stuff that has been allowed to happen via consolidation, merger, or pure homegrown that simply hasn't been prosecuted because recent administrations had an alternate theory that monopolies are OK if it benefits consumers via lower prices.
That's not incompatible with violations in other circumstances. For example, Google releases Android for free, resulting in low prices for mobile operating systems. Competing operating systems may be put out of business, but customers benefit from lower prices and this should be fine if anyone can still choose to use a competing OS -- or fork of Android -- should they prefer it.
Whereas, Google uses tying to its dominant services to ensure that Google Play is the only viable app store on Android, then takes a 30% cut. High margins don't result in lower prices and neither does excluding competitors who might take a smaller cut, so they should be slapped down for this.
Google adds remote attestation and encourages third parties to rely on it even though it makes third party apps dependent on Google's version of the system, creating a barrier to entry for forks or competitors. This kind of thing should be prohibited, because otherwise people are not choosing Google's offering because it provides the best value for money, they're choosing it because Google manufactured a way to shut out competitors who might do better.
The theory isn't the problem. Taking a competitor's market share because customers choose your product for having a better price is not bad. The bad is making it harder for customers to choose competing alternatives they might actually prefer.
The problem is the application. The company comes up with some claim that their anti-competitive moat is there to benefit customers by providing security etc. and get away with it even though it doesn't really provide security or there are viable alternatives that provide security without restricting competition.